In element desktop under lab i think you can already activate the new Rust encryption (which I would not really recommend though)

Under advanced you can enable swipe to change language. Then you can swipe up from space to cycle through your languages. I find it quick enough. No idea about gifs but holding return you can insert emojis.

Different purposes, i personally use a notes app for stuff where i dont care about the when. But a chat is perfect if you want to have date+time stamps with quick notes, e.g., a workout log.

depending on what you do there are large benefits, for me they are executable code blocks (i.e. jupyter like experience) and way better latex support (if you type equations that are more involved this is rather important).

Hmm thats strange, nautilus is definitely themed for me, apart from symlinking and setting the general gtk theme, I think the only thing that I did in addition is setting the following in settings.ini

[Settings]
gtk-application-prefer-dark-theme=true
gtk-icon-theme-name=Papirus-Dark
gtk-theme-name=Catppuccin-Macchiato-Compact-Mauve-Dark

For me cattpuccin also works with libadwaita apps if you symlink the config in gtk-4.0 folder of the theme to .config/gtk-4.0 or is it something more than the colors you are missing for libadwaita apps? 🙈